Search

Although the technique of coronary stenting has remarkably improved long-term results in recent years, (sub)acute thrombosis and late restenosis still remain problems to be solved. Metallic surfaces were regarded as thrombogenic, due to their positive surface charges, and stenosis resulted from the activation and proliferation of vascular smooth muscle cells (VSMCs). In this study, a unique surface modification method for metallic surfaces was studied using a self-assembled monolayer (SAM) technique. The method included the deposition of thin gold layers, the chemisorption of disulfides containing functional groups, and the subsequent coupling of PEG derivatives or heparin utilizing the functional groups of the disulfides. All the reactions were confirmed by ATR-FTIR and XPS. The surface modified with sulfonated PEG (Au-S-PEG-SO3) or heparinized PEG (Au-S-PEG- Hep) exhibited decreased static contact angles and therefore increased hydrophilicity to a great extent, which resulted from the coupling of PEG and the ionic groups attached. In vitro fibrinogen adsorption and platelet adhesion onto the Au- S-PEG-SO3 or Au-S-PEG-Hep surfaces decreased to a great extent, indicating enhanced blood compatibility. This decreased interaction of the modified surfaces should be attributed to the non-adhesive property of PEG and the synergistic effect of sulfonated PEG. The effect of the surface modification on the adhesion and proliferation of VSMCs was also investigated. The modified Au-S-PEG-SO3 or Au-S-PEG-Hep surfaces also exhibited decreased adhesion of VSMCs, while the deposited gold layer itself was effective. The enhanced blood compatibility and the decreased adhesion of VSMCs on the modified metallic surfaces may help to decrease thrombus formation and suppress restenosis. It would therefore be very useful to apply these modified surfaces to stents for improved functions. A long-term in vivo study using animal models is currently under way. [ABSTRACT FROM AUTHOR]

High-performance liquid crystals (LCs) driven at a 0.9 V threshold were demonstrated on very thin HfO2 films with vertical (homeotropic) alignment by ion bombardment. Atomic layer deposition was used to obtain LC orientation on ultrathin high-quality films of double-layer HfO2/Al2O3. X-ray photoelectron spectroscopy indicated that full oxidization of HfO2 film surfaces was induced by ion bombardment, shifting the Hf 4f spectra to lower binding energies. The increased intensities of the Hf 4f peaks after ion bombardment confirmed that nonstoichiometric HfOx was converted to the fully oxidized HfO2 surfaces. [ABSTRACT FROM AUTHOR]

Using ion-beam (IB) irradiation, liquid crystals (LCs) were vertically aligned (VA) on a γ-Al2O3 alignment film. Atomic-layer deposition was used to orient the LCs on high-quality γ-Al2O3 alignment films. The LC molecule orientation indicates the vertical direction of the atomic-layer-deposited γ-Al2O3 alignment films. X-ray photoelectron spectroscopy showed that IB irradiation changed the chemical structure, shifting the Al–O binding energy and altering the Al–O bonding intensity. The low-voltage transmittance characteristics of the VA LC displays on the γ-Al2O3 alignment films were also measured, showing reduced voltage and power requirements. [ABSTRACT FROM AUTHOR]

Recently, extracellular vesicles (EVs) have been developed as therapeutic targets for various diseases. Biodistribution is crucial for EVs intended for therapeutic purposes because it can determine the degree of on‐ and off‐target effects. This study aimed to explore techniques to evaluate the biodistribution of unmodified EVs. We devised a novel quantitative polymerase chain reaction (qPCR)‐based assay to detect unmodified EVs by targeting mitochondrial deoxyribonucleic acid (mtDNA), a constituent of EVs. We focused on specific mtDNA regions that exhibited homologous variations distinct from their rodent mtDNA counterparts to establish this analytical approach. Herein, we successfully designed primers and probes targeting human and rodent mtDNA sequences and developed a highly specific and sensitive qPCR method. Furthermore, the quantification range of EVs isolated from various cells differed based on the manufacturer and cell source. IRDye 800CW‐labelled Expi293F EV mimetics were administered to the animals via the tail vein to compare the imaging test and mtDNA‐qPCR results. The results obtained from imaging tests and mtDNA‐qPCR to investigate EV biodistribution patterns revealed differences. The results revealed that our newly developed method effectively determined the biodistribution of unmodified EVs with high sensitivity and reproducibility. [ABSTRACT FROM AUTHOR]

We measured the absolute frequency of the 1S0–3P0 transition of 171Yb atom confined in a one-dimensional optical lattice relative to the SI second. The determined frequency was 518 295 836 590 863.38(57) Hz. The uncertainty was reduced by a factor of 14 compared with our previously reported value in 2013 due to the significant improvements in decreasing the systematic uncertainties. This result is expected to contribute to the determination of a new recommended value for the secondary representations of the second. [ABSTRACT FROM AUTHOR]

We analyze both the s- and p-wave collision induced frequency shifts and propose an over-π pulse scheme to cancel the shifts in optical lattice clocks interrogated by a Rabi pulse. The collisional frequency shifts are analytically solved as a function of the pulse area and the inhomogeneity of the Rabi frequencies. Experimentally measured collisional frequency shifts in an Yb optical lattice clock are in good agreement with the analytical calculations. Based on our analysis, the over-π pulse combined with a small inhomogeneity below 0.1 allows a fractional uncertainty on a level of 10−18 in both Sr and Yb optical lattice clocks by canceling the collisional frequency shift. [ABSTRACT FROM AUTHOR]

We propose a fiber ring laser that operates in a single longitudinal mode by incorporating unpumped erbium-doped fiber as a saturable absorber filter. This laser can be discretely tuned to a 25-GHz-spacing grid that precisely matches ITU-T (International Telecommunication Union, Telecommunication Standardization Sector) grids, which are reference frequencies for optical communication systems. This laser has a signal-to-source spontaneous emission ratio higher than 60 dB, and the lasing frequencies of 361 channels are matched to ITU-T grids with excellent power flatness. With one channel of this fiber laser, we place the reference frequency near the absolute frequency reference (AFR, 193.1 THz). The relative frequency stability of the laser and the frequency offset from the AFR were less than 1.6×10−8 (integrated time, 5 min) and 30 MHz, respectively. [ABSTRACT FROM AUTHOR]

In ideal diffraction-limited optical microscopy imaging depth is limited by the multiply scattered wave. Here, the authors present a space gating method, based on an acoustic focus in the object plane and reconstruction using only the acousto-optically modulated ballistic wave, and demonstrate increased imaging depth in scattering samples.

Our previous big data analyses reported a strong association between CHI3L1 expression and lung tumor development. In this present study, we investigated whether a CHI3L1-inhibiting natural compound, ebractenoid F, inhibits lung cancer cell growth and migration and induces apoptosis. Ebractenoid F concentration-dependently (0, 17, 35, 70 µM) and significantly inhibited the proliferation and migration of A549 and H460 lung cancer cells and induced apoptosis. In the mechanism study, we found that ebractenoid F bound to CHI3L1 and suppressed CHI3L1-associated AKT signaling. Combined treatment with an AKT inhibitor, LY294002, and ebractenoid F synergistically decreased the expression of CHI3L1. Moreover, the combination treatment further inhibited the growth and migration of lung cancer cells and further induced apoptosis, as well as the expression levels of apoptosis-related proteins. Thus, our data demonstrate that ebractenoid F may serve as a potential anti-lung cancer compound targeting CHI3L1-associated AKT signaling.

Ballistocardiographs (BCGs), which record the mechanical activity of the heart, have been a subject of interest for several years because of their advantages in providing unobtrusive physiological measurements. BCGs could also be useful for monitoring the biological signals of infants without the need for physical confinement. In this study, we describe a physiological signal monitoring bed based on load cells and assess an algorithm to extract the heart rate and breathing rate from the measured load-cell signals. Four infants participated in a total of 13 experiments. As a reference signal, electrocardiogram and respiration signals were simultaneously measured using a commercial device. The proposed automatic algorithm then selected the optimal sensor from which to estimate the heartbeat and respiration information. The results from the load-cell sensor signals were compared with those of the reference signals, and the heartbeat and respiration information were found to have average performance errors of 2.55% and 2.66%, respectively. The experimental results verify the positive feasibility of BCG-based measurements in infants.